Remove duplicated from multidimensional array

Have an array with this expression $products[] = $product[$category_id][$product_id]:

$products = array(
    33 => array(
        31 => array(
            'model' => 'Product 4',
            'product_id' => 31,
            'sku' => '',
            'ean' => '1234',
            'price' => '80.0000'
        ),
        8733 => array(
            'model' => 'qqq',
            'product_id' => 8733,
            'sku' => '',
            'ean' => '1000',
            'price' => '344.6281'
        )
    ),
    25 => array(
        30 => array(
            'model' => 'Product 3',
            'product_id' => 30,
            'sku' => '',
            'ean' => '250',
            'price' => '50.4132'
        ),
        31 => array(
            'model' => 'Product 4',
            'product_id' => 31,
            'sku' => '',
            'ean' => '1234',
            'price' => '80.0000'
        )
    )
);

I need remove duplicated product in php and result must be:

$products = array(
    33 => array(
        8733 => array(
            'model' => 'qqq',
            'product_id' => 8733,
            'sku' => '',
            'ean' => '1000',
            'price' => '344.6281'
        )
    ),
    25 => array(
        30 => array(
            'model' => 'Product 3',
            'product_id' => 30,
            'sku' => '',
            'ean' => '250',
            'price' => '50.4132'
        ),
        31 => array(
            'model' => 'Product 4',
            'product_id' => 31,
            'sku' => '',
            'ean' => '1234',
            'price' => '80.0000'
        ),
    )
);

I have tried this:

$cleared_products = array();

        foreach ($products as $category_id => $category_products) {
            foreach ($category_products as $product_id => $product) {
                if (isset($cleared_products[$category_id][$product_id])) {
                    
                    unset($products[$category_id][$product_id]);
                } else {
                    
                    $cleared_products[$category_id][$product_id] = $product;
                }
            }
        }

But does not work...

Edited to explain why I need that I need to generate XML and no products can be duplicated. It doesn't matter that they belong to a different category. XML recipient rules...

The problem with your code is that you check if the product exists within it's category. In your example the duplicate product is in two categories.

We can adjust it easily by keeping track of the ID you added.

$cleared_products = array();
$productIds = array();

foreach ($products as $category_id => $category_products) {
    foreach ($category_products as $product_id => $product) {
        if (in_array($product_id, $productIds)) {
            continue;
        } else {
            $productIds[] = $product_id;
            $cleared_products[$category_id][$product_id] = $product;
        }
    }
}

Important note: You don't have control out of which category the item will be filtered

So the expected result is not matched with this code. If you define the priority of categories and sort on this, you can delete it where wanted.